#include <stdio.h>

//C的编译器不认知extern "C"
#ifdef __cplusplus
extern "C"
{
#endif

int add(int x, int y)
{
    return x + y;
}

#ifdef __cplusplus
}//end of extern "C"
#endif
 
int main(int argc, char *argv[])
{
    printf("Hello world\n");
    return 0;
}

